Volumes and Data
Exercise 9.1: Create a ConfigMap
Overview
Container files are ephemeral, which can be problematic for some applications. Should a container be restarted the files will be lost. In addition, we need a method to share files between containers inside a Pod.
A Volume is a directory accessible to containers in a Pod. Cloud providers offer volumes which persist further than the life of the Pod, such that AWS or GCE volumes could be pre-populated and offered to Pods, or transferred from one Pod to another. Ceph is also another popular solution for dynamic, persistent volumes.
Unlike current Docker volumes a Kubernetes volume has the lifetime of the Pod, not the containers within. You can also use different types of volumes in the same Pod simultaneously, but Volumes cannot mount in a nested fashion. Each must have their own mount point. Volumes are declared with spec.volumes and mount points with spec.containers.volumeMounts parameters. Each particular volume type, 24 currently, may have other restrictions. https://kubernetes.io/docs/concepts/ storage/volumes/#types-of-volumes
We will also work with a ConfigMap, which is basically a set of key-value pairs. This data can be made available so that a Pod can read the data as environment variables or configuration data. A ConfigMap is similar to a Secret, except they are not base64 byte encoded arrays. They are stored as strings and can be read in serialized form
Create a ConfigMap
There are three different ways a ConfigMap can ingest data, from a literal value, from a file or from a directory of files
- We will create a ConfigMap containing primary colors. We will create a series of files to ingest into the ConfigMap.
First, we create a directory primary and populate it with four files. Then we create a file in our home directory with our
favorite color.
student@lfs458-node-1a0a:~$ mkdir primary student@lfs458-node-1a0a:~$ echo c > primary/cyan student@lfs458-node-1a0a:~$ echo m > primary/magenta student@lfs458-node-1a0a:~$ echo y > primary/yellow student@lfs458-node-1a0a:~$ echo k > primary/black student@lfs458-node-1a0a:~$ echo "known as key" >> primary/black student@lfs458-node-1a0a:~$ echo blue > favorite - Now we will create the ConfigMap and populate it with the files we created as well as a literal value from the command
line.
student@lfs458-node-1a0a:~$ kubectl create configmap colors \ --from-literal=text=black \ --from-file=./favorite \ --from-file=./primary/ configmap/colors created - View how the data is organized inside the cluster.
student@lfs458-node-1a0a:~$ kubectl get configmap colors NAME DATA AGE colors 6 30s student@lfs458-node-1a0a:~$ kubectl get configmap colors -o yaml apiVersion: v1 data: black: | k known as key cyan: | c favorite: | blue magenta: | m text: black yellow: | y kind: ConfigMap <output_omitted> - Now we can create a Pod to use the ConfigMap. In this case a particular parameter is being defined as an environment
variable.
student@lfs458-node-1a0a:~$ vim simpleshell.yaml apiVersion: v1 kind: Pod metadata: name: shell-demo spec: containers: - name: nginx image: nginx env: - name: ilike valueFrom: configMapKeyRef: name: colors key: favorite - Create the Pod and view the environmental variable. After you view the parameter, exit out and delete the pod.
student@lfs458-node-1a0a:~$ kubectl create -f simpleshell.yaml pod/shell-demo created student@lfs458-node-1a0a:~$ kubectl exec -it shell-demo \ -- /bin/bash -c ’echo $ilike’ blue student@lfs458-node-1a0a:~$ kubectl delete pod shell-demo pod "shell-demo" deleted - All variables from a file can be included as environment variables as well. Comment out the previous env: stanza
and add a slightly different envFrom to the file. Having new and old code at the same time can be helpful to see and
understand the differences. Recreate the Pod, check all variables and delete the pod again. They can be found spread
throughout the environment variable output.
student@lfs458-node-1a0a:~$ vim simpleshell.yaml <output_omitted> image: nginx # env: # - name: ilike # valueFrom: # configMapKeyRef: # name: colors # key: favorite envFrom: - configMapRef: name: colors student@lfs458-node-1a0a:~$ kubectl create -f simpleshell.yaml pod/shell-demo created student@lfs458-node-1a0a:~$ kubectl exec -it shell-demo \ -- /bin/bash -c ’env’ HOSTNAME=shell-demo NJS_VERSION=1.13.6.0.1.14-1~stretch NGINX_VERSION=1.13.6-1~stretch black=k know as key favorite=blue <output_omitted> student@lfs458-node-1a0a:~$ kubectl delete pod shell-demo pod "shell-demo" deleted - A ConfigMap can also be created from a YAML file. Create one with a few parameters to describe a car.
student@lfs458-node-1a0a:~$ vim car-map.yaml apiVersion: v1 kind: ConfigMap metadata: name: fast-car namespace: default data: car.make: Ford car.model: Mustang car.trim: Shelby - Create the ConfigMap and verify the settings.
student@lfs458-node-1a0a:~$ kubectl create -f car-map.yaml configmap/fast-car created student@lfs458-node-1a0a:~$ kubectl get configmap fast-car -o yaml apiVersion: v1 data: car.make: Ford car.model: Mustang car.trim: Shelby kind: ConfigMap <output_omitted> - We will now make the ConfigMap available to a Pod as a mounted volume. You can again comment out the previous
environmental settings and add the following new stanza. The containers: and volumes: entries are indented the
same number of spaces.
student@lfs458-node-1a0a:~$ vim simpleshell.yaml <output_omitted> spec: containers: - name: nginx image: nginx volumeMounts: - name: car-vol mountPath: /etc/cars volumes: - name: car-vol configMap: name: fast-car <comment out rest of file> - Create the Pod again. Verify the volume exists and the contents of a file within. Due to the lack of a carriage return in
the file your next prompt may be on the same line as the output, Shelby.
student@lfs458-node-1a0a:~$ kubectl create -f simpleshell.yaml pod "shell-demo" created student@lfs458-node-1a0a:~$ kubectl exec -it shell-demo -- \ /bin/bash -c ’df -ha |grep car’ /dev/sda1 20G 4.7G 15G 25% /etc/cars student@lfs458-node-1a0a:~$ kubectl exec -it shell-demo -- \ /bin/bash -c ’cat /etc/cars/car.trim’ Shelby - Delete the Pod and ConfigMaps we were using.
student@lfs458-node-1a0a:~$ kubectl delete pods shell-demo pod "shell-demo" deleted student@lfs458-node-1a0a:~$ kubectl delete configmap fast-car colors configmap "fast-car" deleted configmap "colors" deleted
Exercise 9.2: Creating a Persistent NFS Volume (PV)
We will first deploy an NFS server. Once tested we will create a persistent NFS volume for containers to claim.
- Install the software on your master node.
student@lfs458-node-1a0a:~$ sudo apt-get update && sudo \ apt-get install -y nfs-kernel-server <output_omitted> - Make and populate a directory to be shared. Also give it similar permissions to /tmp/
student@lfs458-node-1a0a:~$ sudo mkdir /opt/sfw student@lfs458-node-1a0a:~$ sudo chmod 1777 /opt/sfw/ student@lfs458-node-1a0a:~$ sudo bash -c \ ’echo software > /opt/sfw/hello.txt’ - Edit the NFS server file to share out the newly created directory. In this case we will share the directory with all. You can
always snoop to see the inbound request in a later step and update the file to be more narrow.
student@lfs458-node-1a0a:~$ sudo vim /etc/exports /opt/sfw/ *(rw,sync,no_root_squash,subtree_check) - Cause /etc/exports to be re-read:
student@lfs458-node-1a0a:~$ sudo exportfs -ra - Test by mounting the resource from your second node.
student@lfs458-worker:~$ sudo apt-get -y install nfs-common <output_omitted> student@lfs458-worker:~$ showmount -e lfs458-node-1a0a Export list for lfs458-node-1a0a: /opt/sfw * student@lfs458-worker:~$ sudo mount 10.128.0.3:/opt/sfw /mnt student@lfs458-worker:~$ ls -l /mnt total 4 -rw-r--r-- 1 root root 9 Sep 28 17:55 hello.txt - Return to the master node and create a YAML file for the object with kind, PersistentVolume. Use the hostname
of the master server and the directory you created in the previous step. Only syntax is checked, an incorrect name
or directory will not generate an error, but a Pod using the resource will not start. Note that the accessModes do not
currently affect actual access and are typically used as labels instead.
student@lfs458-node-1a0a:~$ vim PVol.yaml apiVersion: v1 kind: PersistentVolume metadata: name: pvvol-1 spec: capacity: storage: 1Gi accessModes: - ReadWriteMany persistentVolumeReclaimPolicy: Retain nfs: path: /opt/sfw server: lfs458-node-1a0a #<-- Edit to match master node readOnly: false - Create the persistent volume, then verify its creation.
student@lfs458-node-1a0a:~$ kubectl create -f PVol.yaml persistentvolume/pvvol-1 created student@lfs458-node-1a0a:~$ kubectl get pv NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE pvvol-1 1Gi RWX Retain Available 4s
Exercise 9.3: Creating a Persistent Volume Claim (PVC)
Before Pods can take advantage of the new PV we need to create a Persistent Volume Claim (PVC).
- Begin by determining if any currently exist.
student@lfs458-node-1a0a:~$ kubectl get pvc No resources found. - Create a YAML file for the new pvc.
student@lfs458-node-1a0a:~$ vim pvc.yaml apiVersion: v1 kind: PersistentVolumeClaim metadata: name: pvc-one spec: accessModes: - ReadWriteMany resources: requests: storage: 200Mi - Create and verify the new pvc is bound. Note that the size is 1Gi, even though 200Mi was suggested. Only a volume of
at least that size could be used.
student@lfs458-node-1a0a:~$ kubectl create -f pvc.yaml persistentvolumeclaim/pvc-one created student@lfs458-node-1a0a:~$ kubectl get pvc NAME STATUS VOLUME CAPACITY ACCESSMODES STORAGECLASS AGE pvc-one Bound pvvol-1 1Gi RWX 4s - Look at the status of the pv again, to determine if it is in use. It should show a status of Bound.
student@lfs458-node-1a0a:~$ kubectl get pv NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE pvvol-1 1Gi RWX Retain Bound default/pvc-one 5m - Create a new deployment to use the pvc. We will copy and edit an existing deployment yaml file. We will change the
deployment name then add a volumeMounts section under containers and volumes section to the general spec. The
name used must match in both places, whatever name you use. The claimName must match an existing pvc. As shown
in the following example.
student@lfs458-node-1a0a:~$ cp first.yaml nfs-pod.yaml student@lfs458-node-1a0a:~$ vim nfs-pod.yaml apiVersion: apps/v1beta1 kind: Deployment metadata: annotations: deployment.kubernetes.io/revision: "1" generation: 1 labels: run: nginx name: nginx-nfs namespace: default resourceVersion: "1411" spec: replicas: 1 selector: matchLabels: run: nginx strategy: rollingUpdate: maxSurge: 1 maxUnavailable: 1 type: RollingUpdate template: metadata: creationTimestamp: null labels: run: nginx spec: containers: - image: nginx imagePullPolicy: Always name: nginx volumeMounts: - name: nfs-vol mountPath: /opt ports: - containerPort: 80 protocol: TCP resources: {} terminationMessagePath: /dev/termination-log terminationMessagePolicy: File volumes: #<<-- These four lines - name: nfs-vol persistentVolumeClaim: claimName: pvc-one dnsPolicy: ClusterFirst restartPolicy: Always schedulerName: default-scheduler securityContext: {} terminationGracePeriodSeconds: 30 - Create the pod using the newly edited file
student@lfs458-node-1a0a:~$ kubectl create -f nfs-pod.yaml deployment.apps/nginx-nfs created - Look at the details of the pod. You may see the daemonset pods running as well.
student@lfs458-node-1a0a:~$ kubectl get pods NAME READY STATUS RESTARTS AGE nginx-nfs-1054709768-s8g28 1/1 Running 0 3m student@lfs458-node-1a0a:~$ kubectl describe pod nginx-nfs-1054709768-s8g28 Name: nginx-nfs-1054709768-s8g28 Namespace: default Node: lfs458-worker/10.128.0.5 <output_omitted> Mounts: /opt from nfs-vol (rw) <output_omitted> Volumes: nfs-vol: Type: PersistentVolumeClaim (a reference to a PersistentV... ClaimName: pvc-one ReadOnly: false <output_omitted> - View the status of the PVC. It should show as bound.
student@lfs458-node-1a0a:~$ kubectl get pvc NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE pvc-one Bound pvvol-1 1Gi RWX 2m
Exercise 9.4: Using a ResourceQuota to Limit PVC Count and Usage
The flexibility of cloud-based storage often requires limiting consumption among users. We will use the ResourceQuota object to both limit the total consumption as well as the number of persistent volume claims.
- Begin by deleting the deployment we had created to use NFS, the pv and the pvc
student@lfs458-node-1a0a:~$ kubectl delete deploy nginx-nfs deployment.extensions "nginx-nfs" deleted student@lfs458-node-1a0a:~$ kubectl delete pvc pvc-one persistentvolumeclaim "pvc-one" deleted student@lfs458-node-1a0a:~$ kubectl delete pv pvvol-1 persistentvolume "pvvol-1" deleted - Create a yaml file for the ResourceQuota object. Set the storage limit to ten claims with a total usage of 500Mi.
student@lfs458-node-1a0a:~$ vim storage-quota.yaml apiVersion: v1 kind: ResourceQuota metadata: name: storagequota spec: hard: persistentvolumeclaims: "10" requests.storage: "500Mi" - Create a new namespace called small. View the namespace information prior to the new quota. Either the long name
with double dashes --namespace or the nickname ns work for the resource.
student@lfs458-node-1a0a:~$ kubectl create namespace small namespace/small created student@lfs458-node-1a0a:~$ kubectl describe ns small Name: small Labels: <none> Annotations: <none> Status: Active No resource quota. No resource limits. - Create a new pv and pvc in the small namespace.
student@lfs458-node-1a0a:~$ kubectl create -f PVol.yaml -n small persistentvolume/pvvol-1 created student@lfs458-node-1a0a:~$ kubectl create -f pvc.yaml -n small persistentvolumeclaim/pvc-one created - Create the new resource quota, placing this object into the low-usage-limit namespace.
student@lfs458-node-1a0a:~$ kubectl create -f storage-quota.yaml \ -n small resourcequota/storagequota created - Verify the small namespace has quotas. Compare the output to the same command above.
student@lfs458-node-1a0a:~$ kubectl describe ns small Name: small Labels:Annotations: Status: Active Resource Quotas Name: storagequota Resource Used Hard -------- --- --- persistentvolumeclaims 1 10 requests.storage 200Mi 500Mi No resource limits. - Remove the namespace line from the nfs-pod.yaml file. Should be around line 11 or so. This will allow us to pass
other namespaces on the command line.
student@lfs458-node-1a0a:~$ vim nfs-pod.yaml - Create the container again.
student@lfs458-node-1a0a:~$ kubectl create -f nfs-pod.yaml \ -n small deployment.apps/nginx-nfs created - Determine if the deployment has a running pod.
student@lfs458-node-1a0a:~$ kubectl get deploy --namespace=small NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE nginx-nfs 1 1 1 0 43s student@lfs458-node-1a0a:~$ kubectl -n small describe deploy \ nginx-nfs <output_omitted> - Look to see if the pods are ready.
student@lfs458-node-1a0a:~$ kubectl get po -n small NAME READY STATUS RESTARTS AGE nginx-nfs-2854978848-g3khf 1/1 Running 0 37s - . Ensure the Pod is running and is using the NFS mounted volume. If you pass the namespace first Tab will auto-complete
the pod name.
student@lfs458-node-1a0a:~$ kubectl -n small describe po \ nginx-nfs-2854978848-g3khf Name: nginx-nfs-2854978848-g3khf Namespace: small <output_omitted> Mounts: /opt from nfs-vol (rw) <output_omitted> - View the quota usage of the namespace
student@lfs458-node-1a0a:~$ kubectl describe ns small <output_omitted> Resource Quotas Name: storagequota Resource Used Hard -------- --- --- persistentvolumeclaims 1 10 requests.storage 200Mi 500Mi No resource limits. - Create a 300M file inside of the /opt/sfw directory on the host and view the quota usage again. Note that with NFS the
size of the share is not counted against the deployment.
student@lfs458-node-1a0a:~$ sudo dd if=/dev/zero \ of=/opt/sfw/bigfile bs=1M count=300 300+0 records in 300+0 records out 314572800 bytes (315 MB, 300 MiB) copied, 0.196794 s, 1.6 GB/s student@lfs458-node-1a0a:~$ kubectl describe ns small <output_omitted> Resource Quotas Name: storagequota Resource Used Hard -------- --- --- persistentvolumeclaims 1 10 requests.storage 200Mi 500Mi <output_omitted> student@lfs458-node-1a0a:~$ du -h /opt/ 301M /opt/sfw 41M /opt/cni/bin 41M /opt/cni 341M /opt/ - Now let us illustrate what happens when a deployment requests more than the quota. Begin by shutting down the
existing deployment.
student@lfs458-node-1a0a:~$ kubectl -n small get deploy NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE nginx-nfs 1 1 1 1 11m student@lfs458-node-1a0a:~$ kubectl -n small delete deploy nginx-nfs deployment.extensions "nginx-nfs" deleted - Once the Pod has shut down view the resource usage of the namespace again. Note the storage did not get cleaned
up when the pod was shut down.
student@lfs458-node-1a0a:~$ kubectl describe ns small <output_omitted> Resource Quotas Name: storagequota Resource Used Hard -------- --- --- persistentvolumeclaims 1 10 requests.storage 200Mi 500Mi - Remove the pvc then view the pv it was using. Note the RECLAIM POLICY and STATUS
student@lfs458-node-1a0a:~$ kubectl get pvc -n small NAME STATUS VOLUME CAPACITY ACCESSMODES STORAGECLASS AGE pvc-one Bound pvvol-1 1Gi RWX 19m student@lfs458-node-1a0a:~$ kubectl -n small delete pvc pvc-one persistentvolumeclaim "pvc-one" deleted student@lfs458-node-1a0a:~$ kubectl -n small get pv NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE pvvol-1 1Gi RWX Retain Released small/pvc-one 44m - Dynamically provisioned storage uses the ReclaimPolicy of the StorageClass which could be Delete, Retain, or
some types allow Recycle. Manually created persistent volumes default to Retain unless set otherwise at creation.
The default storage policy is to retain the storage to allow recovery of any data. To change this begin by viewing the
yaml output.
student@lfs458-node-1a0a:~$ kubectl get pv/pvvol-1 -o yaml .... path: /opt/sfw server: lfs458-node-1a0a persistentVolumeReclaimPolicy: Retain status: phase: Released - Currently we will need to delete and re-create the object. Future development on a deleter plugin is planned. We will
re-create the volume and allow it to use the Retain policy, then change it once running.
student@lfs458-node-1a0a:~$ kubectl delete pv/pvvol-1 persistentvolume "pvvol-1" deleted student@lfs458-node-1a0a:~$ grep Retain PVol.yaml persistentVolumeReclaimPolicy: Retain student@lfs458-node-1a0a:~$ kubectl create -f PVol.yaml persistentvolume "pvvol-1" created - We will use kubectl patch to change the retention policy to Delete. The yaml output from before can be helpful in
getting the correct syntax
student@lfs458-node-1a0a:~$ kubectl patch pv pvvol-1 -p \ ’{"spec":{"persistentVolumeReclaimPolicy":"Delete"}}’ persistentvolume/pvvol-1 patched student@lfs458-node-1a0a:~$ kubectl get pv/pvvol-1 NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE pvvol-1 1Gi RWX Delete Available 2m - View the current quota settings
student@lfs458-node-1a0a:~$ kubectl describe ns small . requests.storage 0 500Mi - Create the pvc again. Even with no pods running, note the resource usage.
student@lfs458-node-1a0a:~$ kubectl -n small create -f pvc.yaml persistentvolumeclaim/pvc-one created student@lfs458-node-1a0a:~$ kubectl describe ns small . requests.storage 200Mi 500Mi - Remove the existing quota from the namespace.
student@lfs458-node-1a0a:~$ kubectl -n small get resourcequota NAME CREATED AT storagequota 2018-08-01T04:10:02Z student@lfs458-node-1a0a:~$ kubectl -n small delete \ resourcequota storagequota resourcequota "storagequota" deleted - Edit the storagequota.yaml file and lower the capacity to 100Mi.
student@lfs458-node-1a0a:~$ vim storage-quota.yaml . requests.storage: "100Mi" - Create and verify the new storage quota. Note the hard limit has already been exceeded
student@lfs458-node-1a0a:~$ kubectl create -f storage-quota.yaml -n small resourcequota/storagequota created student@lfs458-node-1a0a:~$ kubectl describe ns small . persistentvolumeclaims 1 10 requests.storage 200Mi 100Mi No resource limits. - Create the deployment again. View the deployment. Note there are no errors seen.
student@lfs458-node-1a0a:~$ kubectl create -f nfs-pod.yaml \ -n small deployment.apps/nginx-nfs created student@lfs458-node-1a0a:~$ kubectl -n small describe deploy/nginx-nfs Name: nginx-nfs Namespace: small <output_omitted> - Examine the pods to see if they are actually running.
student@lfs458-node-1a0a:~$ kubectl -n small get po NAME READY STATUS RESTARTS AGE nginx-nfs-2854978848-vb6bh 1/1 Running 0 58s - As we were able to deploy more pods even with apparent hard quota set, let us test to see if the reclaim of storage takes
place. Remove the deployment and the persistent volume claim.
student@lfs458-node-1a0a:~$ kubectl -n small delete deploy nginx-nfs deployment.extensions "nginx-nfs" deleted student@lfs458-node-1a0a:~$ kubectl -n small delete pvc/pvc-one persistentvolumeclaim "pvc-one" deleted - View if the persistent volume exists. You will see it attempted a removal, but failed. If you look closer you will find the
error has to do with the lack of a deleter volume plugin for NFS. Other storage protocols have a plugin.
student@lfs458-node-1a0a:~$ kubectl -n small get pv NAME CAPACITY ACCESSMODES RECLAIMPOLICY STATUS CLAIM STORAGECLASS REASON AGE pvvol-1 1Gi RWX Delete Failed small/pvc-one 20m - Ensure the deployment, pvc and pv are all removed.
student@lfs458-node-1a0a:~$ kubectl delete pv/pvvol-1 persistentvolume "pvvol-1" deleted - Edit the persistent volume YAML file and change the persistentVolumeReclaimPolicy: to Recycle.
student@lfs458-node-1a0a:~$ vim PVol.yaml .... persistentVolumeReclaimPolicy: Recycle .... - Add a LimitRange to the namespace and attempt to create the persistent volume and persistent volume claim again.
We can use the LimitRange we used earlier
student@lfs458-node-1a0a:~$ kubectl -n small create -f \ low-resource-range.yaml limitrange/low-resource-range created - View the settings for the namespace. Both quotas and resource limits should be seen.
student@lfs458-node-1a0a:~$ kubectl describe ns small <output_omitted> Resource Limits Type Resource Min Max Default Request Default Limit ... ---- -------- --- --- --------------- ------------- -... Container cpu - - 500m 1 - Container memory - - 100Mi 500Mi - - Create the persistent volume again. View the resource. Note the Reclaim Policy is Recycle.
student@lfs458-node-1a0a:~$ kubectl -n small create -f PVol.yaml persistentvolume/pvvol-1 created student@lfs458-node-1a0a:~$ kubectl get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS ... pvvol-1 1Gi RWX Recycle Available ... - Attempt to create the persistent volume claim again. The quota only takes effect if there is also a resource limit in effect.
student@lfs458-node-1a0a:~$ kubectl -n small create -f pvc.yaml Error from server (Forbidden): error when creating "pvc.yaml": persistentvolumeclaims "pvc-one" is forbidden: exceeded quota: storagequota, requested: requests.storage=200Mi, used: requests.storage=0, limited: requests.storage=100Mi - Edit the resourcequota to increase the requests.storage to 500mi
student@lfs458-node-1a0a:~$ kubectl -n small edit resourcequota .... spec: hard: persistentvolumeclaims: "10" requests.storage: 500Mi status: hard: persistentvolumeclaims: "10" .... - Create the pvc again. It should work this time. Then create the deployment again
student@lfs458-node-1a0a:~$ kubectl -n small create -f pvc.yaml persistentvolumeclaim/pvc-one created student@lfs458-node-1a0a:~$ kubectl -n small create -f nfs-pod.yaml deployment.apps/nginx-nfs created - View the namespace settings.
student@lfs458-node-1a0a:~$ kubectl describe ns small <output_omitted> - Delete the deployment. View the status of the pv and pvc
student@lfs458-node-1a0a:~$ kubectl -n small delete deploy nginx-nfs deployment.extensions "nginx-nfs" deleted student@lfs458-node-1a0a:~$ kubectl get pvc -n small NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE pvc-one Bound pvvol-1 1Gi RWX 7m student@lfs458-node-1a0a:~$ kubectl -n small get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORA... pvvol-1 1Gi RWX Recycle Bound small/pvc-one - Delete the pvc and check the status of the pv. It should show as Available
student@lfs458-node-1a0a:~$ kubectl -n small delete pvc pvc-one persistentvolumeclaim "pvc-one" deleted student@lfs458-node-1a0a:~$ kubectl -n small get pv NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORA... pvvol-1 1Gi RWX Recycle Available ... - Remove the pv and any other resources created during this lab.
student@lfs458-node-1a0a:~$ kubectl delete pv pvvol-1 persistentvolume "pvvol-1" deleted
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